The prior art recognizes that improvement of any parameter of kidney function, such as inducing natriuresis or improving blood flow through the kidney by decreasing renal vascular resistance, is an important component of the medical treatment of either hypertension and kidney dysfunction.
D. W. Cushman et al., Biochemistry, 16 5484 (1977), reported that a number of N-acylprolines were potent inhibitors of angiotensin converting enzyme. Receptor site requirements were alleged to be responsible for the specificity of structure necessary in that series for ACE inhibition.
The compounds of this invention are believed to be novel in structure and in biological activity.